| 摘要 |
PURPOSE: To feed machines commonly with power while electrically insulating a low voltage circuit from a power circuit and to prevent a power supply voltage from being transmitted to a keyboard, display elements or sensors. CONSTITUTION: Network voltages L1, L2 are connected with a safety transformer 4 which ensures that the network voltages L1, L2 are not transmitted to a control circuit 1, a display 7, a sensor 3, a keyboard 6, etc. A signal is transmitted from an input control circuit 1 to a power control circuit 11 through a photocoupler 14 and a signal line 13. The photocoupler 14 ensures that an undue high voltage is not transmitted from the power control circuit 11 to the input control circuit 1. Consequently, the control circuit 1 is protected sufficiently against touching the network voltage. |
